Such an unlikely pairing, the two of you are. If you'd ask Shatter before her transfer to Earth what the chances were of a Decepticon ever having romantic relations with another species were, she'd say "0", yet here the two of you were, living in the middle of nowhere. She told Dropkick that she was only using you because your house was far from the public eye and they could do as they pleased since you were a willing host, but she'd never dare tell him of the true nature of you two's relationship which formed long ago... it'd be best to not test the waters.

...

It was coming to an end of a long day of work for you, right now, it was Dropkick's turn to do the "babysitting" or so he calls it. You need a car to get in and out of work, and he destroyed yours in a hissy fit over discussing an Autobot that escaped their clutches, so he'll be the sacrifice for today. The rides you two share are quiet, despite his more bombastic attitude, he often mutes himself when it is only the two of you. Is it because he refuses to speak to you because the next thing he must say is an apology and he can't even fathom the thought of steeping low enough to apologise to a damn human. Either way, when you made it home, he transformed back into his base form, basically spitting you out of him.

You were now at the drive of your home, he was muttering to himself as he walked towards the garage to speak to Shatter who'd just got back from tracking to escaped Autobot rebel, but, she had another thing on her mind. The red Decepticon walked out from the garage, bendhing down to avoid damaging the top of the opening of it.

"Play nice boys."

She'd say in her all too familiar jest at the two of you, he confidence being portrayed gracefully by her tone. She walked out to see if you were alright, which you were, Dropkick was getting gentler in how he treats you. But she can't give him any hints of the both of your actual relationship, so she phrased her question carefully.

"Have you been marked in any way?"

Subtle.